1. For recent reviews, see e.g. Binder, K.: In: Fundamental problems in statistical mechanics V. Cohen, E.G.D. (ed.), p. 21. Amsterdam: North Holland 1980; Fischer, K.H.: Phys. Status Solidi (b) (1982); Souletie, J., Rammal, R.: Preprint; Mydosh, J.A.: In: Lecture Notes in Physics. Vol. 149. Berlin, Heidelberg, New York: Springer 1981
2. Sherrington, D., Kirkpatrick, S.: Phys. Rev. Lett.35, 1792 (1975)
3. Kirkpatrick, S., Sherrington, D.: Phys. Rev. B17, 4384 (1978)
4. Parisi, G.: J. Phys. A13, L115 (1980); Philos. Mag. B41, 677 (1980)
5. Parisi, G., Toulouse, G.: J. Phys. Lett. (Paris)41, L361 (1980)